1. Field of the Invention
The present invention is directed to processes for the preparation of optically-active cyanomethyl esters and novel catalysts therefor.
2. Description of the Prior Art
Stereoisomers of cyanomethyl esters of alpha-chiral carboxylic acids or the acids themselves usually have different effects in biological systems. In the past, it usually had not been simple to prepare such optically-active cyanomethyl esters directly because the corresponding chiral alpha-hydroxynitriles were not always readily available. Even when these optically-active alpha-hydroxynitriles were available or became more readily available, the optically-active acids were not always readily accessible. Often, the optically-active acids were obtained by classical resolution, which was usually time consuming and not practical on a large scale.
The present process provides a process for preparing optically-active cyanomethyl esters of alpha-chiral carboxylic acids in high yield by a direct synthesis method, avoiding the cumbersome classical resolution of the corresponding optically-active acids and alcohols.